Multistage condenser for internal combustion engines



Aug. 18, 1970 I o. RSENF 3,524,499

MULTISTAGE CONDENSER FOR INTERNAL COMBUSTION ENGINES Filed Sept. 10, 1968 I I v 2 Sheets-Sheet 1 I FIGZ) o 0 0 S 0 0 STEAM o 0 0 A AND 0 0 WATER p a 4 0 4 WATER v 6 CONDENSATION A b 0 A b If: iNvENTOR OAKLAN R. SENF Aug. 18, 1970 o. R. SENF MULTISTAGE CONDENSER FOR INTERNAL COMBUSTION ENGINES Filed Sept; 10, 1968 2 Sheets-Sheet 2 FIG2 INVENTOR OAKLAN R, SENF BM JQ wggif z;

ATTORNEYS United States Patent O U.S. Cl. 165-110 8 Claims ABSTRACT OF THE DISCLOSURE A vapor cooling system for internal combustion engines including an upper tank and a lower tank separated by finned heat exchange tubes, the upper tank being sealed from the lower tank and containing a number of steam condensing tubes connecting the upper tank to the exchange tubes which, in turn, are connected to the lower tank. The lower tank is provided with a temperature sensing vent to extract air from the system prior to the condensation phase of the steam-water entering the system and to automatically close upon the system reaching a predetermined temperature to seal the system.

REFERENCE TO RELATED APPLICATIONS The subject matter of the present invention is in part related to US. application Ser. No. 85,910, filed Jan. 30, 1961 now Pat. No. 3,082,753 for a Vapor Phase Cooling System for Internal Combustion Engine.

BACKGROUND OF THE INVENTION Field of the invention The present invention refers to an ebullient or vapor cooling system for internal combustion engines including diesel, gasoline and natural gas engines having a substantially closed sealed coolant circulatory system.

Description of the prior art Vapor phase cooling systems have been in general use throughout the industry for some time due to the successful experiences with vapor cooling relative to higher efficiency and longer engine life. This holds true especially in engine installations required to operate for long periods with a minimum of servicing such as stationary engines, or engines for commercial lift trucks and con struction vehicles.

Generally, the vapor phase cooling system consists of circulating the coolant from the engine cooling jacket through a heat exchanger or condenser and back into the engine cooling jacket for recirculation. To prevent loss of coolant and assure efiicient condensation thereof the system must preferably 'be closed which requires an air vent to remove air from the system prior to the operation thereof. The heat transfer action in a vapor condenser would be extremely hindered by the presence of air or other non-condensable gases.

Normally, in prior vapor cooling arrangements a gravity type of a simple condensing phase has been used. In these systems, steam-water is ejected into a first tank and then through a core section of the condenser or radiator into a second tank from which the condensate flows back along the same path for re-use. By this arrangement both the steam-water and the condensate are at all times in intimate contact and thus the prior system does no allow efficient condensation and suitable cooling of the condensate due to the inefficient heat transfer caused by the continuously circulating and intermixing of the steam-water and condensate. In other words, the most beneficial effect of vapor cooling, that is, condensing and cooling the condensate is lost.

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Furthermore, in previously used vapor cooling systems, difliculties were encountered in regard to installation and the cooling fan arrangement. This is of no great importance in stationary engine installations since in most instances ample space is available. However, if considered for installation in a moving vehicle space becomes of paramount importance since the system has to be fitted in the place allowed for the conventional radiator. Thus a gravity type of condenser would not be desirable due to its space requirement and the necessary intricate shrouding for the cooling fan.

A further problem encountered in vapor cooling systems is bleeding of the air from the system which is important since the presence of air or other non-condensable gases adversely affects the condensing process.

In addition, in the vertical radiator or condenser arrangement necessary in moving vehicle installations, a pump would be required to pump the condensate back into the engine water jacket from the lower portion of the radiator. This together with the cooling fan, has to fit into the space normally alloted for the conventional radiator.

Previously used vapor cooling systems employing conventional vertical radiators located in front of the engine had to employ a compensating chamber in addition to the radiator or condenser to take care of heat expansion of the coolant. This additional structure is relatively difficult to fit under the hood of an ordinary motor vehicle and combined with the added expense has so far found no practical application.

Accordingly, the primary object of the present invention is to provide an efiicient vapor cooling system for internal combustion engines adapted to fit into the place of the conventional radiator of the engine.

The construction and operation of the present novel vapor cooling system will be more clearly ascertained by the following detailed description in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an internal combustion engine for a vehicle embodying the features of the present invention;

FIG. 2 is an enlarged fragmentary cross sectional view through the radiator or condenser shown in FIG. 1 of the drawings;

FIG. 3 is a schematic diagram illustrating the stratified condensing process taking place in the radiator or condenser shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the present invention is illustrated as incorporated in a conventional internal combustion engine 10 having awater jacket 12 adapted to circulate coolant within the cylinder block 14.

The present novel cooling system for the engine 10 is a substantially closed circulatory system, the coolant being circulated through the water jacket 12 of the 'block 14 and through the cylinder head 16. A combined outlet and return tube L7 is provided to communicate with the cylinder head 16 and the upper chamber 20 of a radiator or condenser 18.

The condenser 18, as will be more fully described in connection with FIGS. 2 and 3, is of novel construction and serves to condense the vapor generated in the engine cooling system during operation of the engine. In general, the condenser 18 comprises an upper chamber 20 and a. lower chamber 22 connected by a core section 24 composed of an assembly of the usual finned tubes 26. A fan 28 driven by a belt drive arrangement 30 from the engine crankshaft may be positioned behind the core section 24 and may be suitably shrouded as at 32 to direct streams of cooling air around the finned tubes 26 to sufficiently cool the vapor condensing within the tubes 26. The lower condenser chamber 22 has an outlet 34 which is in communication with a pump 36 adapted to continuously pump the condensate which drains from the tubes 26 into the lower chamber back into the engine block 14 by means of a conduit 38. The pump 36 may be belt driven or electrically driven depending on type of the engine installation.

With further reference to FIG. 2, a temperature sensing vent valve 40 may be provided at the upper condenser chamber to expel all air or other non-condensable gases from the condenser 18 at the start of the operation. The vent valve is thermostatically controlled to close the vent outlet upon reaching a certain operating temperature within the upper chamber to prevent any vapor from escaping through the vent which would result in a loss of coolant from the system. In general, the vent valve 40 is of a construction and operates in the manner as disclosed in US. Pat. No. 3,082,753 assigned to applicants assignee and for a detailed description reference should be made to the aforesaid patent. For purpose of explanation it will sufiice that the valve 40 is provided with a thermostat 42 extending within the upper chamber 20 which is connected to a valve housing 44 positioned outside of the chamber 20 and provided with a vent opening 46 which in the open position of the valve communicates with the atmosphere. The lower chamber 22 is vented by means of a conduit 49 extending from the lower chamber into the valve housing 44 to be in communication with the vent outlet 46 when the thermostat is open. Elficient venting of the condenser 18 upon operation of the engine without expelling any vapor through the vent is accomplished as follows. As the steam-water mixture from the engine passes through the pipe 17 and into the upper chamber 20 when the engine is in operation and prior to the steam-water reaching the steam state, that is, at approximately 180 F., the thermostat 42 acts immediately to close the vent outlet 46 to prevent any vapor loss through the vent. This is an important function, since the engine is required to operate at long durations without servicing. If vapor would be expelled through the vent the resultant loss in coolant would reduce the efiiciency of the cooling system considerably and the coolant would have to be replenished periodically to the required operating level. Providing a thermostat in the upper chamber 20 to be in intimate contact with the incoming steam-water and venting only through the lower chamber 22 assures immediate closing of the vent upon reaching of the steam-state temperature before any vapor will be lost.

Condensation of the vapor in the condenser 18 is accomplished in a novel manner necessitated by the requirement to fit the condenser into the space normally provided for the conventional radiator. To this end the condenser 18 is constructed as follows: the bottom of the upper chamber 20 is provided with a shroud or baffie 48 which extends across the chamber from side to side and end to end over the upper open ends of the finned tubes 26 and which is attached to the side Walls 19 and 21 of the chamber and which is sealed air and water tight around the edges as at 50. The bafiie 48 is spaced from the ends of the tubes 26 a certain distance for a reason to be explained and slopes rearwardly downwardly as indicated at 52 to be below the lower level of the inlet pipe opening 54 which communicates with the pipe 17. The front portion 56 of the baffle 48 is level is provided with openings 58 which receive a number of upstanding tubes 60 sealed around the edges as at 62. The tubes 60 extend upwardly within the chamber 20 to close to the top 64 of the chamber to be spaced a relative small distance 63 therefrom. The tubes 60 thus provide the only communication between the upper chamber 20 and the finned tubes 26. By means of the tube and baffle arrangement the upper chamber 20 is divided into a first chamber 66 which is the turbulence chamber receiving the steam- Water mixture from the engine by way of pipe 17. The thermostat 42 for the air valve 40 is located in this chamber to immediately sense the temperature of the steamwater mixture. A second chamber 68 is provided between the underside of the baffie 48 and the open top of the finned tubes 26 of the core 24.

This arrangement provides a multistage or stratified condensing process as schematically illustrated in FIG. 3, and as described in the following: as the mixture of hot steam-Water ST-W enters the turbulence chamber 66 it impinges against the sides of the chamber and against the tubes 60. As the temperature of the mixture approaches the steam state and prior thereto the thermostat 42 acts to close the air valve 40 thus completely sealing the system from the atmosphere prior to the steam state to allow none of the vapor to escape. The condensing process continues as the steam and water in the turbulence chamber 66 separate causing the water W to settle at the bottom of the chamber on bafile 48 whereas the steam rises upwards to the top of the chamber. This stage is indicated in the top strata in the diagram in FIG. 3. The water W settled at the bottom of the chamber 66 fiows by gravity as facilitated by the sloping portion 52 of the bafile 48 back into tube 17 for return to the engine water jacket 12. Due to the impingement of the steam against the tubes and against the top of the chamber 66 its speed of flow is considerably slowed as opposed to the turbulence flow. The steam then enters the tubes 60 from the top further decreasing its speed of flow due to the narrow space 63 allowed between the open ends of the tubes and the top 64 of the chamber. The steam ST then descends down the tubes 60 and exits from the bottom of the tubes 60 into the bottom chamber 68 while it expands. Due to the intimate surface contact of the steam with the inner walls of the tubes 60 and with the surfaces of the bottom chamber 68 a heat transfer takes place initiating the condensation process. As the cooled steam enters the finned tubes 26 in the core 24 from the bottom chamber 68 the heat transfer action is increased and the steam is rapidly cooled off due to the cooling air circulating around the finned tubes between the fins 25 thus finalizing the condensation process and the condensed steam in the form of water droplets 70 drops down from the finned tubes into the lower chamber 22 of the condenser 18. These stages of condensation are schematically illustrated in the lower half of the diagram in FIG. 3. The condensate C collected in the lower chamber 22 is then continuously pumped by means of pump 36 for return to the engine water jacket along conduit 38.

The foregoing condensation cycle is continuously repeated as long as the engine is in operation to provide a highly efiicient vapor cooling system.

Initially, the condenser 18 is empty and no coolant will be introduced into it except what comes from the engine during operation. The engine water jacket 12 is initially filled with coolant by means of a filler neck 72 located near the cylinder head 16. The coolant may be plain water and additive or, to provide anti-freeze protection, an aqueous solution such as that marketed as Dowtherm 209 may be used.

By the present novel multi-stage condenser a highly efficient vapor cooling system for internal combustion engines has been provided which is especially adaptable in engine installations required to operate at relatively long durations with a minimum of service.

The present novel condenser structure is interchangeable with conventional radiator structures so that no alterations under the hood of a vehicle engine installation will be necessary.

The present invention may be embodied in certain other forms without departing from the spirit and essential characteristics thereof, therefore, the present embodiment is to be considered in all respects as illustrative only and not,

restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description.

What is claimed is:

1. A multistage, stratified, closed vapor cooling system for an internal combustion engine having a liquid coolant jacket, comprising a condenser having a sealed turbulence chamber adapted to receive a steam-liquid mixture ejected from said engine coolant jacket, means within said turbulence chamber to separate said steam-liquid mixture into steam and liquid and return said separated liquid to said engine coolant jacket, a second chamber separated from said turbulence chamber by a series of condensing tubes, means for directing said steam separated in said turbulence chamber through said condensing tubes into said second chamber, means condensing said steam as it passes through said steam directing means and said condensing tubes, and means to return said condensed steam as a condensate liquid to said engine coolant jacket.

2. In the vapor cooling system defined in claim 1, said means in said turbulence chamber comprising a bafie separating said turbulence chamber from said condensing tubes, tubes connected to said baffle extending to the top of said turbulence chamber and in communication with said condensing tubes for passage of steam therethrough.

3. In the vapor cooling system defined in claim 1, said condensing means including fins provided on said condensing tubes adapted for the guidance of air around said condensing tubes.

4. In the vapor cooling system defined in claim 1, said means to return said condensed steam to said engine coolant jacket, including an outlet in said second chamber, a pump in communication with said outlet and a pipe connected between said pump and said engine coolant jacket.

5. In the vapor cooling system defined in claim 2, said baflle being constructed to provide a gravity type pump for said separated liquid to allow return of said separated liquid to said engine coolant jacket by its own gravity.

6. In combination with an internal combustion engine including a closed circulatory vapor cooling system, a surface condenser having an upper tank and a lower tank separated by a series of air cooled condensing tubes, means in said upper tank dividing said upper tank into a turbulence chamber in direct communication with said engine and a steam compression and expansion chamber in communication with said condensing tubes, a conduit connecting said lower tank with said engine including pump means, means to seal said turbulence chamber from said steam chambers and thermostatically closable means to extract air from said lower tank.

7. In the combination defined in claim 6, said means in said upper tank comprising a bafile across the lower portion of said upper tank, tubes connected to said bafile for communication of steam, said baflle dividing said upper tank into said turbulence chamber and said steam compression and expansion chamber, and an inlet tube connecting said turbulence chamber with said engine adapted to convey coolant from said engine to said turbulence chamber.

8. In the combination defined in claim 7, said bafile having a surface adjacent said tube connection sloping downwardly towards said inlet tubeto provide a head of liquid settling on said baflle for return movement through said inlet tube into said engine.

References Cited UNITED STATES PATENTS 995,314 6/1911 Abs 165-73 1,649,247 11/ 1927 Muir 123-41 .1 3,082,753 3/1963 Bullard 12341.08 3,282,333 11/1966 Jensen 165-111 ROBERT A. OLEARY, Primary Examiner T. W. STREULE, Assistant Examiner US. Cl. X.R. 

